<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01JS的三种引入方式</title>
</head>
<body>
<button onclick="alert('请先登录!')">点击即玩</button>
<button onclick="console.log('请先登录!')">点击即玩</button>
<button class="btn">js测试</button>
</body>
<script src="01.js">
    // document.getElementById('btn').onclick = function (){
    //     alert('请先登录!')
    // }
    // document.querySelector('.btn').addEventListener('click',function (){
    //     alert('asdfasdfasdfsadfsadffafda')
    // })
</script>
</html>